Multi-millionaire businessman Paul Sykes has an established pedigree of hostility towards the EU.
Sykes: Passionate on EU
The 61-year-old Yorkshire businessman has dipped into his vast fortune for the cause spending an estimated £6m financing eurosceptic campaigns.
He quit the Tory party in 1991 over opposition to the Maastricht Treaty after a passionate meeting with Michael Howard.
But the campaign began in earnest at the 1997 General Election when he gave cash to eurosceptic Conservative MPs.
He followed this up with a pledge in 1998 to "use every means possible" to persuade British voters to say "No" in a referendum on the single currency.
He said he would "raise hellfire to get the message across".
In 1999 he joined forces with the Referendum Movement - the successor to the Referendum Party set up by the late Sir James Goldsmith - pledging £20m to a newly formed Democracy Movement.
And his generosity has not been restricted to the UK. Mr Sykes gave £500,000 to help the successful anti-euro campaign in Denmark.
He rejoined the Tory party in 2000 when William Hague took over as leader.
But just before the 2001 election the Conservative leadership cancelled his membership over his tough anti-Europe stance.
He switched support to UKIP and pledged to blow his fortune.
Most recently he gave up to £1m to the party - half of UKIP's fighting fund for June's European elections.
Mr Sykes has come a long way to become one of Britain's wealthiest businessmen.
Born the son of a miner in Barnsley, he left school without any qualifications.
Before the age of 15 he had had five jobs - the first of which was working as a tyre fitter.
At 18 he began his first business dismantling old buses and selling the engines as scrap to developing countries in the Far East.
Syekes returned briefly to Tory ranks after William Hague became leader
A decade on he moved into property and hit the big-time building one of the first out-of-town shopping centres in Britain, the Meadowhall development in Sheffield.
He also made money on developing the internet with his firm Planet Online becoming the country's largest internet provider.
In 1998 he sold it for £85m to Energis - which at that time carried around 40% of the UK's internet traffic.
With a business empire stretching across the Channel, Mr Sykes is estimated to be worth around £500m.